Evaluating workers' comp prescription drug trends is crucial because pharmaceuticals comprise a significant part of employers' spending on injured workers, said one expert.

Narcotics, anticonvulsants, anti-inflammatory medications and antidepressants remain among the most commonly prescribed drugs for workers compensation claimants, according to separate analyses released last week.

While observers note that the data is limited to the clients of the two pharmacy benefit managers conducting the studies, the PBMs' information still provides valuable insight into prescribing trends and costs that affect employers.

"The cost of the drugs is an extremely large piece of the comp pie," Noonan said.

Prescription drugs account for 19 percent of all workers comp medical expenses, according to a study last September by Boca Raton, Florida-based NCCI Holdings Inc.

Aside from analyzing the most frequently used drugs to treat injured workers, the reports from Express Scripts Inc. and Progressive Medical Inc. provide insight into the prescribing of compounded prescriptions, which have come under increasing scrutiny by the workers' comp industry, and on the rising use and prices of topical medications known as dermatologicals.

In addition, St. Louis-based Express Scripts' "Workers' Compensation Drug Trend Report" states that more than $2.1 billion in workers comp prescription expense waste occurs annually across the United States, which it said is due largely to prescribing more expensive medications when lower-cost equivalent drugs are available.

Express Scripts said its report is based on a review of millions of claims, while Progressive Medical said its evaluation included more than 200,000 claims representing about 3 million transactions.

Results drawn from studies comparing data from several PBMs would be more helpful and less biased than reports based on claims data from each PBM's customer base, Noonan said.

"I would be much more interested in how one (PBM) compares to the other," Noonan said.

Nonetheless, the reports released last week provide insight to help employers in directing their medical network providers, clinics and other workers' comp providers to get the best outcome on claims, he said.

The studies are valid in their reporting of price changes and general trends that are likely felt systemwide, said Joseph Paduda, principal at Health Strategy Associates L.L.C. in Madison, Connecticut.

The PBMs' annual reports do help the workers' comp industry stay abreast of significant trends, such as prescribing trends involving compound drugs, which are expensive because pharmacists must mix them manually, other observers say.

As for highly addictive narcotic drugs, Express Scripts reported that narcotic analgesics—such as OxyContin, Tramadol and oxycodone—accounted for 38 percent of its clients' workers' comp pharmaceutical expenses and 34 percent of their prescription drug claim utilization during 2011.

In addition to their generally high expense, narcotics are widely prescribed for workers' comp claimants because pain is a common result of workplace injuries.

But Express Scripts said it helped its clients reduce narcotics utilization by 4.2 percent in 2011.

"That is reflective of the importance of programs to manage utilization for that therapy class ... not necessarily just from the perspective of controlling overall costs, but maintaining the safety of injured workers," said Jennifer Kaburick, Express Scripts' St. Louis-based director of workers' comp product management.

Though the narcotic drug category is still the largest percentage of overall meds being filled, Progressive Medical said it helped its clients cut their total spending for the narcotics, achieving a 3.9 percent reduction in 2011.

"This is largely due to Progressive Medical's emphasis on conducting interventions earlier in the life cycle of a claim," according to the PBM's "2012 Workers' Compensation Mediation Trends Report."

"Globally, we are (also) seeing anticonvulsants, anti-inflammatories, antidepressants and muscle relaxants in the top category of prescriptions," said Tron Emptage, Progressive Medical's chief clinical officer.

Express Scripts, meanwhile, reported an increase in the utilization and price of dermatologicals such as Flector, Lidoderm and Voltaren gel. The topical medications often are prescribed with oral pain medications, said Sharon Frazee, St. Louis-based vice president of research and analysis for Express Scripts.

Although dermatological prescriptions do not cost as much as narcotics, they remain expensive and may not have a generic alternative, so state mandates requiring the use of available generics would not apply, according to Express Scripts.

"The average cost per prescription is $248.56 for (dermatologicals), so they are relatively expensive medications," Frazee said.